Located east of the Rainbow Range of South Tweedsmuir Park, the park landscape is unique in its variety of volcanic landforms, alpine environments, lakes, grassland, forest, and wetland habitat.

The Itcha Range and Ilgachuz Range are examples of isolated shield volcanoes, rising up to 2,400 metres above sea level. These ranges are situated in the rain shadow of the Coast Mountains, and support a high diversity of plant and animal species.

The South Carrier and Chilcotin Peoples have inhabited the Itcha Ilgachuz area for centuries, leading a nomadic lifestyle and travelling whenever necessary to find food and resources. The Itcha Ilgachuz was used by First Nations to hunt and trap animals such as beaver, caribou, moose, and martin, and to gather plants, roots, and obsidian in summer. Traditional fishing camps were also located in the area.

Trade was important to the South Carrier Peoples. The historic Alexander Mackenzie Heritage (Grease) Trail north of the park was one of the main routes used to trade furs, berries, and obsidian. Today, large portions of this trail still exist and are used by hikers and horseback riders. An archaeological site has been identified near one of the obsidian quarries in the Itcha Ilgachuz.

Unmaintained hiking trails and horse riding trails exist throughout Itcha Ilgachuz Provincial Park, and cross-country ski touring and winter camping are possible. Wilderness and backcountry camping is allowed, but no facilities are provided other than pit toilets. There are 2 cabins located near Itcha Lake for public use. They hold approximately 6 people each and are very rustic. People need to be prepared to camp outside in the event the cabins are full. These cabins are maintained by the Itcha Cabin Society and donations towards their maintenance are requested.

The Itcha and Ilgachuz Ranges are surrounded by provincially significant salmon spawning and rearing rivers. Though fish habitat is limited within the park by steep terrain, Itcha Lake does support populations of rainbow trout and bull trout.

Itcha Ilgachuz Provincial Park provides habitat for numerous wildlife species, including wolves, cougars, black bear, grizzly bear, mule deer, caribou, moose, mountain goat, and California bighorn sheep. The park protects extensive spring and summer caribou habitat, critical caribou calving areas, and limited but critical winter habitat for the largest remaining woodland caribou population (approximately 1,500) in southern British Columbia. The Caribou populations are vulnerable, and sensitive to human disturbance. The most northerly population of California bighorn sheep in North America, and extensive summer and winter moose range are also found within the park.

Other furbearers include beaver, muskrat, coyote, marten, red fox, wolverine, river otter, bobcat, and lynx. The area’s wetland habitats also support waterfowl, game birds, songbirds, amphibians, and reptile.

The trailhead for this park is reached by travelling about 11 miles (18 km) north of Anahim Lake on Lessard Lake Road, then about 40 miles (64 km) on a so-so gravel road (check conditions beforehand with BC Parks in Williams Lake).